To experience most of the quality content in this game, you only really need to do the MSQ, the Hildibrand storyline, the raid storylines (Alexander/Omega/Eden), Alliance raid (Void Ark/Ivalice), and the trial storylines (Warring Triad/Four Lords/Werlyt). Beyond that, you're looking at diminishing returns. To experience the job storylines or Bozja, you're going to have to do a lot of grinding, time that could have been spent completing a JRPG or a visual novel or doing something else which you might enjoy more than grinding for tidbits of story.

There are a lot of guides telling you to do a lot of stuff, so it might seem overwhelming, but really you don't really need to do everything. When I played WoW, I tried being a completionist, but I've since realized that it was a lot of time wasted for stuff that I didn't really enjoy or stuff that doesn't really matter. It's okay to finish the stuff you're interested in and then move on with your life. Don't get caught in the skinner box trap. I guess it might be doable if you're young and have unlimited free time.